Internal combustion engine



Aug. 18, 1931. H. JOHNSON INTERNAL COMBUSTION ENGINE Filed Oct. 26, 1929 3 Sheets-Sheet l Inventor:

1931. H. JOHNSON 1,819,897

INTERNAL COMBUSTION ENGINE Filed Oct. 26. 1929 3 Sheets-Sheet 2 an I 4 1e Z 2 as 4 g Inventor? Aug. 18, 1931. H. JOHNSON 1,819,897

INTERNAL COMBUSTION ENGINE Filed Oct. 26, 1929 3 Sheets-Sheet 3 42 g #7510 00/4 EQylg-L [n U677, i072 Fig. 8. I

V Patented Aug. 18, 1931 UNITED STATES MILTON JOHNSON, OF BATON BQUGE, LOUISIANA COMBUSTION ENGINE Application fled mmac, 1929. serial- 10.401664.

My invention relates to improvements in internal combustion engines designed to develop mechanical energy by the useof a piston reciprocating in a cylinder in which the mixture of air and gas or vapor is compressed, burned, and expanded and the objects of my improvement are, first, to provide means by which the clearance volume of the workin cylinder may be changed While the machine is in operation; second, to provide means for regulating the quantity of mixture contained in this cylinder at the beginning of compression so that this quantity shall bear a definite ratio to the clearance volume of the cylinder; and third, to

provide means for automatically restrictmg the changes in clearance volume and quantity of mixture within certain predetermined limits.

I attain these objects by the mechanism illustrated in the three accompanying drawings, in which- Fig. 1 is a plan view of the machine as it appears with the protecting hood 57 re- 2 moved; Fig. 2 is a vertical section on the line AA, Fig. 1; Fig. 3 is a vertical section on the line BB, Fig. 1; Fig. 4 is a vertical section on the line 0-0, Fig. 1; Fig. 5 is a vertical section on the line EE, Fi 1;'

Fig. 6 is a vertical section on the line -F, Fig. 2; Fig. 7 is a verticalsection on the line D-D, Fig. 1; and Fig.8 is a diagram showing the wiring connections of the controlling motor. Figs. 9 and 10 are drawings show- 86 ing the action of the inlet valve cam on its follower. Similar numerals refer to similar parts throu bout the drawin The line -I, Fig. 2, mar s the plane of separation of the working cylinder 3 and its 4 head. In this head is provided a cylinder 2 communicating freely through its 0 en inner end with the combustion space 0 cylinder 3. The upper end of this auxiliary cylinder 2 is closed by the piston 4, and the clearance volume of the working cylinder 3 is made up of the space between its head and the upper face of piston 5 when the latter is at the top of its stroke plus that portion of the volume of cylinder 2 which is below piston 4. This piston 4 is actuated through the of 15 is still in contact with the cylindrical connecting rod 6 and the crank 7 by the shaft 8, so that a half-rotation of this shaft suffices to vary the clearance volume of the o .workmg cyl nder from a mlmmum value of the action of the cam 13 on its follower.

This follower comprises two elements indicated on the drawings by the numerals 14 and 15. The first element, 14 has a reciprocatin motion only, being gui ed'by the stem 16 sli ing in the hole 17 bored in the c linder casting and by the two downwar y projecting lugs 18 which bear against the camshaft 12 and prevent rotation of 14. The

second element, 15, fits loosely in a vertical slot in 14 as shown in Fi 2, 6, 9, and 10, and slides freely in this s ot in a plane perpendicular to the the axis of the camshaft 12. Itoscillates about a pin 23 in the upper end of the rocker arm 25 which is secured to the .shaft 26. This shaft is capable of partial rotation in either direction so as to cause displacement horizontally of the pin 23 and through it of element 15. The lower face of 15 is shaped at its free end like that of 14, so that when 15 is at its extreme right hand position the lower faces of 14 and 15 are flush with each other. In this position therefore the counterclockwise rotation of the cam 13 raises and lowers elements 14 and 15 simultaneously and element 15 has no sep arate effect on the motion of the push rod 11.

But when element 15 is displaced to the left by the motion of rocker arm 25, the face of cam 13 engages the lower face of 14 and begins raising the latter while the lower face portion of cam 13 and consequently 15 is still 5 the free end of 15 has been'raised until its upper face has come into contact with point 24; of 14, as shown in Fig. 10. Consequently 14 cannot descend until the'cam has rotatedenough further to release 15. Thus the opening ofthe inlet valve is effected by the action of the cam directly upon the lower face of 14 and takes place at the same point in every cycle of action of the machine, while the closing of this valve is controlled by the action of the cam upon the lower face of 15 and may be delayed to any desired extent by moving 15 the proper distance toward the left.

As compression cannot begin until the inlet valve 9 is closed, the quantity of mixture in the cylinder at the instant compression starts may be very exactly regulated by the proper adjustment of shaft 26. The cam shaft 12 is so connected by gearing to the main shaft of the engine that it rotates in a counter-clockwise direction with an angular velocity equal to one-half that of the main shaft in a 4-stroke cycle engine.

Shaft 8, which by its rotation controls the clearance volume of the working cylinder as explained above, is actuated through the worm gear 27 by the worm 28 keyed to the shaft 29. This latter shaft carries also a spirally grooved cylinder 30 which imparts motion through the pin 31 to the sliding sleeve 32 and the latter actuates the rocker arm 33 which is keyed to shaft 26- and so controls the time of closing of valve 9 and consequently the quantity of mixture left in the working cylinder at the beginning of compression.

As the same shaft 29 controls both the clearance volume of the working cylinder and the quantity of mixture left in this cylinder at the beginning of compression it is obvious th at by properly designing the spiral groove in the cylinder carried by it the compression ratio may be made to have any desired value at any point of the power range of the machine.

Normally this groove would be so designed that the compression ratio and consequently the pressure and temperature of the mixture at'the end ofthe compression stroke would be approximately constant regardless of the quantity of mixture contained in the cylinder.

The exhaust valve may be operated by a cam and push rod of the usual type causing it to open and close at fixed points of'the engine cycle, or it may be actuated by a cam and follower of the same tvpe as those shown and described for controlling the inlet valve. In the latter case the cam and follower would be designed to close the valve at the end of the exhaust stroke and to open it during the power stroke whenever the pressure within the working cylinder fellto that of the atmosphere.

Shaft 29 may be driven through suitable disengaging gearing by the main shaft of the machine itself or by some outside source of energy. I-prefer to drive it by a small independent direct-current motor 34 carrying on its shaft 3511 worm 36 meshing with a gear 37 keyed to shaft 29. The current for oper-' ating this motor is supplied from a storage battery or other external source and the wiring connections are arranged as shown in Figs. 5 and 8. The field winding of the motor is connected in series in one of thebattery leads so that current always flows through it in the same direction whenever either switch 38 or 39 is closed. The switches 38 and 39 are double pole push button switches and, as will be noted from Fig. 8, the connections are so arranged that when switch 38 is closed current passes in such a direction through the armature winding of the motor as to make it rotate clockwise, while closing switch 39 reverses the direction of flow of the current and consequently the direction of rotation of the motor.

The apparatus shown at 40 in Fig. 1 and in detail in Fig. 5 is a safety device designed to prevent shaft 8 from making more than a half-rotation in either direction. When switchv 38 is closed the current actuating the motor flows through the device from binding post 41 to binding post 42, and shaft 8 rotates in a counterclockwise direction. When lug 43 on this shaft comes in contact at point 44 with the short arm of bell-crank lever 45 the slightest further rotation of the shaft will rotate this lever about its journal 46 thus breaking the contact between terminals 47 and 49 and stopping the motor. Similarly when switch 39 is closed the current flows from binding post 42 to binding post 59 and shaft 8 rotates clockwise until lug 43 strikes against the short arm of bell-crank lever 48 and breaks the contact between terminals 49 and 50, again stopping the motor.

The closing of switches 38 and 39 may be effected either by hand or foot pressure or automatically by any suitable device actuated by a change in speed or torque of the main shaft of themachjne, and the switches are so located and designed that both cannot be closed at the same time, and that they will open automatically as soon as they are relieved of the premure tending to close them.

Thelubrication of the machine is effected partly by the splash system and partly by a rotary pump installed in a housing 51 at the bottom of the oil drip pan 52 and driven from the cam-shaft through the same shaft which actuates the distributor of the electric ignition system. The oil discharged from this pump is forced upward through a passage cored out in the cylinder and cylinder head castings and thence as shown in Fig. 7 into the hollow axle 53 on which the valve rocker arm 10 and the exhaust valve rocker arm 58 are journaled. Holes through the wall of, this hollow axle communicate with longitudinal passa provided in the rocker arms so that the oi is conducted to both ends of the rocker arms where it flows out over the tops of the valve stems and ush rods. The excess not used up in the lu rication ofthe valve stems and rocker arms drains back through the annular spaces around the push rods and is collected in the oil chamber 54, whence it flows bygravity through suitable ducts to all the bearings located below this level. If the pump su plies oil to this chamber faster than thesev ucts remove it the surplus passes oil through the overflow pipe 55 and finds its way back to the oil reservoir from which the pump draws its supply.

The cup ofpiston 4 is kept partly full of oil which is carried up by the capillary action .of the fibrous pad 56 and so lubricates the walls of cylinder 2. The bearings of shaft 8 are also kept lubricated from this same source by wicks which are not shownin the drawings.

The carburetion or mixing apparatus, the ignition system, the cooling system, the intake and exhaust piping and the timing gears may be of any usual standard type and are therefore not shown or described.

The cycle of operation of the machine is as follows: The throttle valve between the carburetor and intake manifold is kept wide open and the amount of power developed by the machine is regulated entirely by varying the position of the piston in the auxiliary cylinder 2 and correspondingly the point of closure of the inlet valve. The cylinder 3 is first completely filled with the air-fuel mix t-ure by the suction stroke of piston 5. When this piston starts back on its compression stroke the mixture is forced out at approximately constant pressure through the inlet valve until the latter closes, and that portion of the mixture which remains in the cylinder is compressed into the clearance space and is then i nited, expanded and discharged in the usual fashion.

In a. two-cycle engine the portion of the mixture which is rejected through the open inlet valve prior to the beginning of compression merely passes back into the scavenging cylinder ready to be used again at the next scavenging stroke.

In a four-cycle engine having as many as two power strokes per revolution, at least one cylinder is at any instant in its suction stroke, and therefore the portion of mixture which is rejected through the open inlet valve on the compression stroke has no tendency to return to the carburetor but is simply drawn through the manifold directly into the cylinder which is taking in its charge. In a four-cycle engine having less than two power strokes per revolution a supplementary check valve must be provided to prevent the rejectacting, and the following claims are intended to cover and include all such applications.

I claim:

1.. In a machine for developing mechanical energy by the compression, combustion and expansion of a mixture of air with an inflammable gas or vapor, the combination of a piston against which the medium exerts its expansive pressure reciprocating in a cy inder fitted with a head containing an auxiliary cylinder communicating at its inner end with the main cylinder and closed at its outer end by a piston which may be moved axially in either direction and to any desired extent while the machine. is in operation so as to vary the volume of this auxiliary cylinder which forms part of the clearance volume of the main cylinder, a source of mechanical energy independent of that developed by the machine itself and means for ap plying this energy so as to obtain the axial motion of the piston to the auxiliary cylinder.

2. In a machine for developing mechanical energy by the compression, combustion and expansion of a mixture of air with an inflammable gas or vapor, the combination of a piston against which the medium exerts its expansive pressure reciprocating in a main or working cylinder, an auxiliary cylinder communicating freely with the combustion space of the main cylinder and a piston fitting closely in this auxiliary cylinder and capable of bein moved axially by a link actuated by a cran attached to or forming part of a shaft which may be rotated in either direction, a source of mechanical energy independent of that developed by the machine itself and means for applying this energy so as to obtain the rotative motlon of the said crankshaft. 3. In a machine for developing mechanical energy by the compression, combustion and expansion of a mixture of air with aninfiammable gas or vapor, the combination of a piston against which the medium exerts its expansive pressure, a cylinder in which this piston. reciprocates, a cylinder head containingan auxiliary cylinder communicating freely at its inner end with the combustion space of the main cylinder, a piston fitting closely in th s auxiliary cylinder, a link connecting this iston with a crankshaft capable of rotating in either direction, a source of mechanical energy independent of that developed by the machine itself, means for applying this independent energy to obtain the rotative motion of the said crankshaft and means for controlling the application and stoppage of this supply of energy.

4. In a machine for developing mechanical energy by the compression, combustion and expansion of a. mixture of air with an inflammable gas or vapor, the combination of a piston against which the medium exerts its expansive pressure reciprocating in a cylinder the clearance volume of which may be varied while the machine is in operation, a valve for admitting the mixture to the cylinder so actuated that the point in the cycle of action of the machine at which it opens remains constant but its time of closing may be varied, a source of mechanical energy independent of that developed by the machine itself, and means for applying this energy to change the clearance volume of the cylinder and time of valve closure.

5. In a machine for developing mechanical energy by the compression, combustion and expansion of a mixture of air with an inflammable gas or vapor, the combination of a piston against which the medium exerts its expansive pressure reciprocating in a cylinder the clearance volume of which may be varied while the machine is in operation and a valve for admitting the mixture to the cylinder so actuated that it closes at a point in the compression stroke which may be varied to conform to the change in clearance volume of the cylinder.

6. In a machine for developing mechanical energy by the compression, combustion and expansion of a mixture of air with an inflammable gas or vapor, the combination of a piston against which the medium exerts its expansive pressure reciprocating in a cylinder the clearance volume of which may be varied while the machine is in operation and a valve for admitting the mixture to the cylinder actuated by a rotating cam through a follower composed of two elements, one of which opens the valve at a definite constant point in the cycle of action of the machine while the other holds the valve open through such portion of the compression stroke of the piston as may be determined by the position of the fulcrum about which it oscillates, the position of this fulcrum being capable of variation while the machine is in operation.

7. In a machine for developing mechanical energy by the compression, combustion and expansion of a mixture of air with an inflammable gas or vapor, the combination of a piston against which the medium exerts its expansive pressure reciprocating in a cylinder the clearance volume of which may be varied while the machine is in operation, a valve for admitting the mixture to this cylinder, a rotating cam for actuating this valve, a follower through which the cam motion is transing rotated through a short are in either direction, means for connecting this shaft with some source of energy and means for controlling the application and stoppage of this supply of energy.

8. In a machine for developing mechanical energy by the compression, combustion and expansion of a mixture of air with an inflammable gas or vapor, the combination of a piston against which the medium exerts its expansive pressure, a cylinder in which this piston reciprocates, an auxiliary cylinder communicating freely with the combustion space of the main cylinder, a piston fitting closely in this auxiliary cylinder and capable of being moved axially in either direction and to any desired amount, a valve for the admission of the mixture to the main cylinder so actuated that its time of opening is at a definite and constant point in the cycle of action of the machine but its time of closing changes in conformity with the axial motion of the piston in the auxiliary cylinder, an electric motor for supplying the energy required to impart motion to said piston and a valve varying mechanism and means for applying the energy developed by said electric motor to said piston and valve varying mechamsm.

9. In a machine for developing mechanical energy by the compression, combustion and expansion of a mixture of air with an inflammable gas or vapor, the combination of a piston against which the medium exerts its expansive pressure, a cylinder in which this piston reciprocates, an auxiliary cylinder communicating freely with the combustion space of the main cylinder, a piston fitting closely in this auxiliary cylinder, a link connecting this piston with a crankshaft capable of rotating in either direction, a valve for admitting the mixture of air and gas or vapor to the main cylinder, a rotating cam for actuating this valve, a follower through which the cam motion is transmitted consisting of two elements one of which has a reciprocating motion only and serves to open the valve at a definite, constant point in the cycle of action of the machine, while the other oscillates about a pin in a rocker arm secured to a shaft capable of being rotated through a short are in either direction, means for connecting this shaft with the crankshaft actuating the piston in the auxiliary cylinder so that they move in such synchronism as to properly adjust the time of closing of the admission valve to the clearance volume of the main cylinder, suitable gearing connecting both these shafts with some source of energy and means for controlling the application and stoppage of this supply of energy while the machine is in operation.

10. In a machine for developing mechanical energy by the compression, combustion and expansion of a mixture of air with an in flammable gas or vapor, the combination of a piston against which the medium exerts its expansive pressure, a main or working cylinder in which this piston reciprocates, an auxiliary cylinder communicating freely with the combustion space of the main cylinder, a piston fitting closely in this auxiliary cylinder, a link connecting this piston to a crank attached to or forming part of a shaft which can be rotated in either direction by an electric motor connected with it by suitable gearing, a lug projecting from this shaft and two levers adapted to be engaged by this lug at the desired limits of rotation of the shaft in such fashion as to break connection in the circuit supplying current to the electric motor actuating the shaft, substantially as described.

11. In a machine for developing mechanical energy by the compression, combustion and expansion of a mixture of air with an inflammable gas or vapor, the combination of a piston against which the medium exerts its expansive pressure reciprocating in a cylinder the clearance volume of which may be varied while the machine is in operation, a valve for admitting the mixture to the cylinder so actuated that the point of the cycle at which it closes may also be varied and a source of energy independent of that developed by the machine itself for effecting these changes in clearance volume and time of valve closing. 7

12. In a machine for developing mechanical energy by the compression, combustion and expansion of a mixture of air with an inflammable gas or vapor, the combination of a piston against which the medium exerts its expansive pressure reciprocating in a cylinder the clearance volume of which may be varied while the machine is in operation and a valve for admitting the mixture to this cylinder so actuated that it closes at such a point in the compression stroke as to maintain an approximately constant 'ratio between the clearance volume of the cylinder and the quantity of mixture left in the cylinder when the admission valve closes.

13. In a machine for developing mechanical energy by the compression, combustion and expansion of a mixture of air with an inflammable gas or vapor, the combination of a piston against which the medium exerts its expansive pressure reciprocating in a cylinder the clearance volume of which may be varied while the machine is in operation, a valve for admitting the mixture to this cylinder so actuated that the point of the cycle at which it closes may also be varied while cylinder and closed at its outer end by a closely fitting piston which may be moved in or out so as to vary the volume of the combustion space, a valve for admitting the mixture to the main cylinder so actuated that the point of the cycle at which it closes may be varied while the machine is in operation, a source of energy independent of that developed by the machine itself, means for applying this external energy to vary the position of the piston in the auxiliary cylinder and the time of admission valve closure and means for controlling the application of this energy.

HAMILTON JOHNSON. 

